Process of firing ceramic products



s m. U6 D2 O9 R1 RP. JOS Il Yml ERi m MA G Nd HMM.;v n l LmF .F1 a wom uwr O0 R P Y E N R m A Patented July 19, 1927.`

unirse STATES PATENT OFFICE.

WILLIAM LEE HANLEY, OF BRADFOBDfPENNSYLVANIA.

PROCESS F FIRING CERAMIC PRODUCTS.

Application mea April 13, 192e, serial' No. 101,678.1lv Renewedvremember 2as 1926.

able extent before `theyare removed. In the iiringchamber of the kiln,whichordinarily occupies a central position with respect to thelength ofthe kiln, it necessarily follows that the upper portion of the kilnchamber is heat-ed to a higher temperature than the lower portionsadjacent to the level of the' car platform.. It therefore follows `thatwhere the cars are loaded throughout with bricks of the same kind, therewill be a va,- riation in color, those in the `upper layers beingsomewhat darker than those in the lower layers. This frequentlynecessitates sorting the finished product in order to meet therequirements as to color of different purchasers, and where severaldifferent kinds of bricks are being manufactured in a plant, and thecars are loaded with bricks of the same kind throughout the differentlayers, it results that the plant will have various shades of each kindof brick continually producedin the kiln. This may be extremelydisadvantageous as where there is large demand for bricks of a certainkind in a `particular color, andmay resultin an oversupply of bricks ofcertain kinds in certain .colors beyond the requirements ofthe trade.This applies particularly to stiff mud bricks in various fini-shes, asfaced brick, smooth finish brick and rough finish, for example, 4all ofwhich are made from the samekind of clay by the stiff mud process. l y

vIn `many plants it is alsocustomary to make both stiff mud bricks andpressed bricks. Pressed bricks are made by compressing a nearly drycomposition in suit.- able molds under heavy vpressure into the "0desired `fornnwhile stiff mud bricks are made by forcing the clayinplastic condition through a mold of required shape to produce arectangular block fromy which the individual `bricks are severed,usually by means portion of the chamber is hotter than necesof wirecutter or other suitable cutting means. The dry pressed brick is acloser or denser' product and .requires firing `at a higher temperature,or for a longer period than the wire cut still'l mud brick, in order toedect the proper burning. For this reason,` it is customary to burn drypressed brick by themselves in order that the vap propriate'temperatureor length of exposure tothe required temperature may be provided toinsure the proper burning, and the stiff mud brick are. separatelyburned under the appropriate temperature condition. VThis is more lorless inconvenient in the operation of `any brickkiln making both kindsof f brick andl frequently necessitates additional 7 handling, and otheradditional expenses of operation in providing for the separate firingvof :dry pressed brick and` wire cut stiff mud brick. For example,conditions may readily arise where it is necessary to manufacturepressed brick in larger quantity thanv is necessary` to fill commercialrequirements, in order to operatethe kiln economically, and during theperiod lthat the kilnis utilized for burning pressed brick, themanufacture of the stiff mud brick is discontinued, andl vice-versa.

' In the operation of a tunnel kiln, it is particularly inconvenient toprovide for the separate firing of` two kinds of brick, with` lout greatinconvenience and additional expense, and if a separate kiln isprovidedl for each` kind. ofV brick, the initial cost will be enormous.4and prohibitive, and as smaller quantities of dry pressed brick areordinarily made, it'would be impractical to fire them commercially andeconomically by lthis method. .7, y 'Y 11n. operating a tunnel kiln forfiring stiff mud brick properly andthoroughly, it is necessary to`maintain such a heat at the lower .part of thering zone or chamber ofthe kiln, aswill insure .the firing of the brick, and this necessarilymeans *that the upper sarylor requiredfor` the purpose of tiring thatclass"ofbri'ck.` `It therefore follows that the upper layersy loneachcar, yas before stated, .are darker than the lower layers. I havefound, however, that. in the ,manufacture of rough surfaced,bri'ck`,"inwhichV the face 0f the brick, intended-tio show when the brick isfvlaid,,hasibeen roughened by wires or otherwise when in the plastic state, forthe purpose of giving it a certain texture, such textured surface brickof the same shade as a smooth brick or faced brick will appear, whenlaid, as several shades darker by reason of the shadows produced on theroughened surface.

In carrying out my present invention, I make use of the foregoing factsand I provide the transporting means, by which the bricks are movedthrough the kiln, ordinarily tunnel cars, with layers ofdifferent kindsof brick, superposed upon each other and so arranged that in theprogress of the carload throughout the kiln, each kind of brick will bebrought to a desired commercially finished condition by the normaltemperature of the horizontal portion of the kiln through which itpasses, so that two or more kinds of brick may be fired simultaneouslyon each car and subjected to the desired temperature conditions withoutthe necessity of heating any portion of the kiln hotter than necessary,thus effecting a great economy of fuel and enabling the plant to producecontinuously various kinds of brick in substantial accordance with thecommercial demands therefor. F or example, I may arrange on each car aseries of bottom rows or layers of wire cut stiff mud bricks toa certainheight, and on top of the stiff mud bricks I may superimpose a pluralityof layers or rows of dry pressed brick, arranged at such a height abovethe bottom of the goods space of the kiln, that the dry pressed brickwill, in passing through the firing Zone or chamber, be acted upon bythe higher temperature of the upper portion thereof, while the wire cutstiff mud brick will be acted upon by the relatively lower temperatureof the lower portion of the firing chamber or zone, thus enabling bothlkinds of brick to be simulf taneously fired at the proper temperaturefor each, obviating the necessity of separate .firing for the two kindsof brick, facilitating the handling of both kinds of brick through theplant continuously, and effecting a great economy of operation and costof manufacture.

As another example of the application of my invention, I may arrangeupon each car .bottom rows or layers of stiff mud brick, having`roughened surfaces, and superimpose upon them rows of stili' mud brickhaving smooth surfaces, so that in passing through the firing chamber ofthe kiln, while the upper layers will be actually somewhat darker thanthe lower layers, the roughened brick will actually7 appear darker thanthey are and will be readily saleable.

As another example of the application of my invention, I may' also loadonto the same car a lower layer or layers of rough surfaced, stiff mudbrick, superimposed upon them a plurality of layers of smooth stiff mudbrick,

and superimposed upon the latter, layers of dry pressed brick, whichwill pass through the hottest portion of the firing chamber, while thestiff mud brick will pass through the lower portions of intermediate andlower temperatures, with the result that all of them will be fired andbrought to commercial condition simultaneously, withoutnecessitatingseparate firings or special pre-heating of one portion of the firingchamber in order to secure the proper firing of brick in anotherportion.

As a mattei' of fact, this invention, which I have successfully carriedinto effect, results in a very material saving in the opera tion of abrick plant.

In some instances a brick plant will also manufacture quarry tile. Thesetile are usually made of very fine clay and constitute a denser productthan ordinary stiff mud brick, and are usually made in the form of athin, flat plate or tile, approximately one inch in thickness and in avariety of sizes, and are usually, although not necessarily, provided ontheir under side with longitudinal grooves. It follows that they requirea high degree of heat to fire them and also that the dried tile beforefiring and during firing, must not be subjected to any severe weight orpressure which would naturally tend to break or warp them so as to makethem unsaleable. As quarry tile are considered almost in a class withhigh grade porcelain tile, and must bc more perfect in texture, form andburn than ordinary brick, any material quantity of defective quarry tileproduced will effect a considerable loss in operation. I have found thatthese quarry tile can be readily burned in a t-unnel kiln operated inaccordance with my present in vention,vby superimposing them upon asuffici-ent number of layers of brick of one or other or any of thevarieties hereinbefore mentioned, or others, so that they will occupy aposition near the top of the kiln and not be subjected to any materialsuperimposed weight. To this end, therefore, my' invention contemplatesthe superimposing upon or in the upper layers on tunnel cars of layersof quarry tile or other fiat tile, and preferably a plurality of suchlayers superimposed upon the layers of brick, so that they will besubjected to the highest temperature in the tunnel kiln without havingto bear any superimposed weight except possibly the weightl of a fewlayers of the tiles themselves.

In the accompanying drawing which illus trates one arrangement forcarrying my invention into effect, f

Fig. l represents a cross section of the firing chamber of a singletunnel kiln and one of the tunnel cars therein, showing it loaded withlayers of pressed brick superimposed upon layers of stiff mud brick.

Fig. 2 illustrates a tunnel car loaded with Vthrough which the tunnelcars, one of which three different kinds of brick, the upper portionbeing pressed brick, the intermediate portion smooth finish stiff mudbrick, and the -lower portion rough surfaced stiff mud brick.

Fig. 3 is a similar View showing'a car loaded with stiff mud brick, theupper layers being smooth finished and the lower layers rough finished.

Fig. 4 is a similar view showing a car loaded with three diderent kindsof brick, upon the upper layers of which are superimposed a plurality oflayers of quarry tile or other flat tile.

Fig. 5 is a perspective view showing a quarry tile, such as isillustrated in Fig. 4.

In the accompanying drawings, 1 represents a cross section of a tunnelkiln which maybe of any usual or preferred construction. I have shown asingle tunnel kiln for convenience of illustration, but it will beunderstood that my invention is equally applicable to the firing ofbricks in twin tunnel kilns of any usual or desired construction. Ihave, in this instance, provided the kiln with sidewalls, 2, and crown,3, and the kiln may be of any desired length, ordinarily approximately400 feet, of which the central portion constitutes the firing Zone orchamber, one end portion constituting the preheating chamber and theother end yportion constituting the cooling chamber, but the particularconstruction and arrangement of the kiln itself forms no Vpart of mypresent invention.

In this instance I have shown the kiln provided in the central ortion,or firing chamber', illustrated in Fig. 1, with an internal baiie wall,4, provided at its upper end with an upwardly and inwardly extending,deflector', 5, and forming between it and one of the walls, 2, apassage, 6, for the pinducts of combustion from a series of furnaces,one of which is indicated at 7 vsup-V ,plied with fuel in any desiredmanner, in this instance by a fuel pipe, 8, air pipe, 9, and dampers orcontrolling valves, 10, 11, whereby the temperature of differentportions of the firing chamber or zone, longitudinally thereof, may becontrolled, so as to provide the desired, gradually increasing heatcurve. I prefer to employ direct firing, as indicated in the drawing,and to withdraw the products of combustion from each furnace by means ofa `contiguous suction pipe or passage, indicated at 12, connected lto aheader 12a, which is in turn connected with an exhaust device, notshown. The `pipe, 12, for each furnace, is preferably provided with adamper, indicated at 12", to facilitate the control of the furnaces.These details, however, are not essential to the invention and any otherform of kiln may be employed. 13, represents the goods space isindicated `at '14, or other transporting means fortthe brick to befired, pass longitudinally. The tunnel cars travel on longitudinaltracks, indicated at 15, in the usual manner, land I prefer to stack thebricks on the tunnel cars .as they are formed, and to pass them while onsaid cars, through a drier, to extract occluded moisture therefrom, :andthen pass them to the kiln, but obviously, they may be dried in otherways and placed on the cars after drying, if preferred. Upon each tunnelcar .I arrange a plurality of superimposed layers in the usual or anydesired manner. In Fig. 1, for example, I have shown the eight lowerlayers or rows Aof stiff mud brick, indicated at 16, and adapted to passthrough the lower portion of the goods space of the firing chamber. Uponthe uppermost layer, 16, of the stiff mud bricks, I superimpose aplurality of layers 17, of dry pressed brick, in this instance, eightrows in number, which are thus given an elevated position in the firingzone and are caused to traverse the upper portion thereof, which is, asbefore stated, hotter than the lower portion, thus providing for theproper firing of both kinds of brick, andsubjecting the pressed brick toa -higher temperature throughout their travel throughthe `firingzone,'than the stiff mud bricks are subjected Ito. It thusv follows that byheatingthe kiln to a vtemperature suficient :to properly fire the stiffmud brick, the dry pressed brick will be fired without additional heatand great economy is thus effected. Y

f In Fig. 1, I'have indicated the dry pressed brick by shading todistinguish them from the stid mud brick, which are not shaded. It willbe readily seenthat in carrying my invention intoedect, the number oflayers of one kind of vbrick or the other may be slightly varied fromtimefto time to meet the commercial Irequirements which naturallyvary,vand all of the brick of each kind will be fired to a morenearly even color than would be the case if the entire car were piledwith brick 'of one kind, so that sorting is lar ely or entirely avoided,and the necessity or storing a large quantity of brick `which `are notimmediately needed for commercial demands, is practically avoided.

In Fig. 2, I have illustrated another application of my invention, `inwhich the car, in-

dicated at 114, is :loaded with a plurality of lower layers, indicatedat 118, of stiff mud rough surfaced brick, indicated by shading with awavy line to distinguish them from the others on the car. As these roughsurfaced brick appear .darker 'than they really are, lthey requirerelatively lower temperature to fire them and bring them to commen cialcondition, than smooth faced brick of thersameicharacter. Above theseare a plu- Lill rality of rows of stift mud brick having smooth texture,and indicated at 11G, and the remaining upper layers of the load on theear comprise a dry pressed brick, indicated at 117. In this instance,the dry pressed brick will be subjected to the hotter temperatureportion of the kiln, and the stiff mud brick `will be fired at lovfertemperature, the rough surfaced brick, 118, being subjected to a louerten'iperature than the intermediately placed smooth surfaced brick. Bythis arrangement the pressed brick will receive the greatest heat and beproperly fired, the smooth faced still' mud brick will receive the nextgreatest heat and be properly fired, and the rough. surfaced brick,which pass through the portions of lowest temiierature in the kiln, willbe properly lired, but Will not be quite as dark as the smooth facedbrick in the layers above, but, owing to their roughencd surface, whichcauses them to appear darker When laid, they rivill be thoroughlymarketable and ivill appear darker than a smooth surfaced brick burnedunder the same conditions anu in the same location on the car. v

In Fig. 3, I have shown another arrangement for carrying my inventioninto effect, in which the car indicated at 214, is loaded with aplurality of layers of rough surfaced stiff mud brick, indicated at 218,above Which are a plurality of layers of smooth surfaced stiff mudbrick, indicated at 216, there being no pressed brick used in thisarrangement. The car so loaded passes through the kiln in which ismaintained the proper temperature to secure the tiring of the stiff mudbrick ivith rough surfaces, indicated at 218, and occupying the lowerpart of the` goods space in the kiln. rIlie layers of smooth brick, 216,will necessarily receive a higher degree of heat than the rough surfacedbrick, 21S, Which will actually be ysomewhat lighter in color, but byreason of their `rough surface, ivill appear darker than they reallyare, thus bringing` both kinds of brick to commercially i'ir d conditionwith the minimum amount of heat.

It will be seen that in each of the various arr-angementsl which arecited as examples of different Ways in which my invention may be carriedinto effect, the kiln need only be heated to such temperature as willcorrectly lire the bricks occupying the lower layers on the cars, toinsure bringingv all of the bricks of the several kinds loaded on thecars to commercially fired condition, with a minimum of variation incolor, and With very great economy of fuel and labor. In a single plantin which I have carried out my invention, I have eifectec an actualsaving in the employment of my invention, of more than $20,000.00 in asingle year.

In F a, I have shown one manner of loading` Where it is desired to burntile, as

quarry tile, in addition to bricks, in the tunnel kiln. In this instancethe car is indicated at 314, and is shown loaded with three differentkinds of brick, but obviously, so far as the location of the tile isconcerned, it may be loaded With other combinations of brick or brick ofany particular or desired kind. In the present instance, the first fourlayers, on the truck, indicated at 318, are stiff mud rough surfacedbrick, the next six layers, for example, indicated at 310, are stiff mudsmooth faced brick, the next four layers, for example, indicated at 317,are a pressed brick, and upon the uppermost layers of brick on the carare arranged a plurality of layers, indicated at 319, of quarry tile,one of which is shown at 319, in Fig. 5. It Will be seen that these tileare thin, being substantially an inch in thickness and may be of anydesired size, and are preferably vprovided on the under face withlongitudinal grooves, indicated at 319). It Will be clearly apparentthat when these tile are in the dried condition, they will be liable tobecome broken or ivarped during their passage through the tiring kiln,if they were piled on the car with heavy superimposed weight upon them,and I therefore preferably arrange them as shown in Fig. 4, on top ofthe topmost layer of brick. This has the further advantage that they arethus subjected to the hottest temperature of the firing' zone of thetunnel vin passing therethrough, and this is desirable, as the quarrytile, before stated, are of greater density than stiif mud brick andrequire exposure to higher temperature or a high temperature for alonger period) than ordinary brick. By placing them at the top of thevload on successive cars, a large output of quarry tile can be producedWithout danger of producing any material quantity of imperfect tile andWithout operating the kiln especially for the production of the quarrytile, thus effecting a great saving in labor and fuel, as it is onlynecessary to heat the firing Zone of the kiln, as before stated, to suchtemperature as to bring` the lowest layers of brick on the cars intocommerical firing condition.

While I prefer to carry my inrention into effect by the employment oftunnel cars and a tunnel kiln, I do not limit myself thereto, as otherforms of brick conveying mech* anism may be employed, and my inventionis also applicable to other types of kiln in Which superimposed rows ofbrick are si1nultaneously fired.

That I claim and desire to secure by Letters Patent is z- 1. The hereindescribed process of tiring brick, which consists in supporting aplurality of layers of brick, placing in the lower layers bricksrequiring relatively lower tem* perature to fire them and bring theminto commerical condition, and placing in the lll() superposed layersbrick `requiring a; higher temperature to lire them-and bring them intocoinn'iercial condition, and subjecting said layers, in 'an enclosingchamber, to heat sufiic-icnt to properly lire the brick of the lowerlayers, whereby the bricks of the upper layers will be subjected to aVhigher temperature and economy oit fuel is attained.

The herein described process oli-firing brick, which consists insupporting a plural-- ity oi' layers ot brick uponmovable conveyingmeans, placing` in the lower layers brick requiringrelatively lowerltemperature to fire them and bring them into commercial condition, andplacing in the upper layers brick ieopuiring` a relatively highertemperature to lire them and bring them into commercial condition,passing said layei's of brick through an enclosing chamber andsubjecting them to firing heat suliicient to properly lire the brick inthe lower layers, the higher A temperature at the upper portion of saidY-fio chan'iber effecting the firing of the brick of the upper layers ata higher temperature and effecting economy of fuel. Y Y

The herein described process oi" firing brick, which consists insupporting a plurality o dry pressed brick in an elevated position abovea plurality of stili mud bricks, and simultaneously subjecting them tohigh temperature within an enclosing chamber.

Ll. The herein described process of `firing brick, which consists insupporting a plurality of stili mud brick and supportinga plurality ofdry pressed brickabove the stiff mud brick, passing them through anenclosing chamber and subjecting them to firing heat su'llicient to tirethe stili mud brick, the temperature kat the vupper portion of saidchamber ellecting the iiring of the dry pressed brick at as highertemperature than the temperature of the lower portion of said chamber,which effects ,the firing of the stili mud brick.

5. The herein described process of firing brick, which consists insupporting a plurality of layers of still mud brick, superiinposingthereupon a plurality of layers of dry pressed brick, and subjectingsaid brick to firing temperature within an enclosing chamber. Y

6. The herein described process of iiring brick, which consists insupporting a plurality of layers of still mud brick, supporting thereonand above the same a plurality of layers ot dry pressed brick andpassing the brick longitudinally through an enclosing` chamber andsubjecting them simultaneously to firingtemperature.

7. The herein described process of tiring brick, which consists insupporting a plurality of layers of brick, supporting a plurality oflayers of brickjof greater density than the first mentioned brick, at ahigher level with respect to and above Said rst mentioned briclnandsubjecting all oit said Ibrick, which consists in supporting a pluralityvoit layers of brick, thev lower layers being composed of stili' mudbrick having a roughened'surtace, and upper layers superimposed thereonb-eing composed of stili" mud smooth brick, and'subjecting layers vofbrickftoheat in an',` enclosing chamber. Y 9; rlhe herein describedprocess otiiring brick,l whichgconsist's `in supporting plurality oflayers of brick, the lower layers being composed of stii mud brickhaving a roughened surface, and upper layers superimposed' thereon beingcomposed of stilil mud smooth brick, and the uppermost layers beingcoinposed'of dry'pressed brick, and subjecting said layers of brickssimultaneously, in an enclosing chamber, to heat suilicient to fire thelowermost layers and bring them into commercial condition.

10.` The herein described process of firing brick, which consistsinloading tunnel cars with layers oi brick, the lower hivers comvprisingstili mud brick having rough surand bring them into commercialcondition, .whereby the brick oi the upper layers will be fired athigher temperature.

i 1l. The herein described process of firing brick, which consists inloading tunnel cars with a plurality oi'llayers of brick, the lowerlayers being composed ot stik' Vmud brick requiring a pre-determinedamount oi' heat to bring them into commercially fired condition, theupper layers being composed of dry Vpressed brick requiring a highertemperature to lire them, passing said cars so loaded through a'.tunnell kiln and subjecting the layers of brick on said cars to heatsuiiicient to secure the commercial liring oi the bricks of the lowerlayer and simultaneously iiring x the dry pressed brick at a highertemperaa ture.

12. The herein described process of tiring brick, which consists iiiloading tunnel cars with superimposed layers oi brick, thelowermostlayers being composed` of ystiif mud brick having 'roughsuitacesgand a plurality of layers superimposed thereon being composedot smooth suriacedstil mud brick.

18. The herein described process oi'ring brick, which consists inloading tunnel cars with a plurality of layers oi' products to be fired,and superimposing upon them at the top olfthe load, a plurality oli'tile, passing the cars so loaded through a tunnel kiln and subjectingthe contents of each car to CII heat suiicient to secure the commercialfiring of the products in the lower layers and simultaneously firingsaid tile at a higher temperature and without superimposed weight orpressure.

14. The herein described process of firing brick, which consists inloading tunnel cars with a plurality of layers of brick, the lowerlayers being composed of brick requiring a pre-determined amount of heatto bring them into commercially fired condition, upper layers beingcomposed of brick requiring a higher temperature to fire them7 andsuperimposed upon the uppermost layers of brick, a plurality ofhorizontal layers of quarry tile, passing said cars so loaded through atunnel kiln and subjecting the loads on said cars to heat sulicient tosecure the commercia'l firing of the bricks of the lower' layers, andsimultaneously tiring the bricks of upper layers at a higher temperatureand said quarry tile .at a still higher temperature, without subjectingsaid quarry tile to .superimposed weight or pressure.

In testimony whereof I afiix my signature.

WILLIAM LEE HANLEY, JR.

